Friction snubber for railway car truck springs



June 9, 1953 H. w. MULCAHY 2,641,463

FRICTION SNUBBER FOR RAILWAY CAR TRUCK SPRINGS Filed 'April 1. 1950 2 Sheets-Sheet 1 HHH""7/,

/ 240/ Invenjor.

11 0/12" W mv'loahy H //fl /o 123 2 June 9, 1953 H. w. MULCAHY 2,641,463

lnvenj or: Jla-rryW 7721/Lgglg Patented June 9, 1953 UN FEED rsi-rmreis PA'LE. m" e1? 1 er.

"FRICTIONSNUBBER FQB; nnrnwnnenn ""TRUCK SPRINGS .rtHarrwW; imhflcaliy, "Chicago; ;Ill assignorto wlfl. rwiMiner Jnc JChiewgo, 111., axiorporationfof Delam-ware filiplicatim'rflfiril 1, 19,50,'S1ii3INd 1535457 1 fi 'lfilaims. (CL-267 4?) 2 -"This"i-nvention relates!*to impre v ements iin -:./improv:ed sho'cki,absorber-comprises broadlyea friction shock absorbers especially i'adapted' for :rcasing: A, azriollower- B;,s1idingly telescoped withuse in ccnnection'wi-th trucksprings 'OeraiLWa ruin itheacasingfrA; azrpluralitypiofc:ruhbenipads cars for snubbing -01" dampening the vertial l C-Ce..-C+-Czand Dvarranged. in-series and-icm action--ei="tne-' springs. Srmpereitingrfiiction: plates E-E and Ee-E inter- -Onebject of :g ,invention metalovid a zcposed-rbetween'adgiacent pads andvulcanized, re-

' friction shock-absorber ofthecharacteit indi- 'speetively,:tosaideadjacent'fpads. sated, including a plurality ef rdbber elements ir'flhercasingAi'stinztherformwi a tubular-memdampen or snub *the action of 'the'tru'ck snrings; a it placed under" both compression'and shear -to .aeber oftreyliiidrical 'transverseorossisection; open mi s-erv end :having a: transverse bottom during compressionof 'thesheckebsorber. va aillazat its iowerriendu The bottom Wall is A 'mOI'BfS'DGCifiC' objectof the inventionis to u providedlwith an upstanding. :conical projection provide -irieti'mci shockabsorber as *setierth in i l l'ionwitsxinnerxside,'fandshzis a central; downt-hepreceding paragraph? wherein thevrribber wardly openingseat H on its outer. side adapted elementsof-the mechanism arearranged-in seriesto face'ommodate :the;-usua1nspringncentering lug ot thex bottomi'spring foll'ower. plate of a cluster Within a casingencl are adapt-elite" be compressed by a-memher which isslidingly'telescoped'within of truck springs. At the open up-per: end", the the casingyeach u b ma ein -separated riasingerrispravicled veitii ithreecircumferentiaily from the adjacent rubber element of "the series -"spaced interior' guideslots l 3 ofbayonet :formaby metal plates which are vulcanizedt the re--2O -tionyeach s10t 13 ha/Ving. a restricted outlet 14 "spective elements," the plates "and *faces' ofithe at its upper end, and a depending stop lug ldto rubber elements" to which the plates'aresecured thelettof the-outlet; as-seen in lii m "being inclined; whereby; when" the mechanism is "-"-Ihefo'l1ower-B eomprises a cylindrical :sleeve compressed, the rubber elements "are placed 1111- p' rt '0n- I fitelescoped :within the upp r iend F'of cler'laoth compression anct'shearto provideyield- :25. .-.the easing Ag; and atransversetopwall ll closing ing resistance, and the plates areforced toslide e pp end 0f the Sleeve P01171011 6 on 'eachother' to "providefr'ictional' resistance. 1 5 i1 i ed ly outwardly b y 'Otherobjectsbfth'e inventionwiirmore'eleari tharsle ve p n Hito *p a p r pher 'appearfrom' the descriptiennnd claims hereinfiangei lflf'ad p d g e w e-' pp e d 'after following. 5of the casing. Atonrestrictxinward movementrof of my improved frictionshock"absbrben Figure I th accomp'gnying drawings" forming a, part riiilheaii'f'flllEwellaBfl lThEEGWall 5115-15 YDI'OViIl'Bd Witha 'of'thisspecification;"Figure ris a"topplan'view d pending:wm l"' inroje i n t on its mderneath-sider :Whichr cooperates with the; top- 2 is a vertical sectionalview',fcerrespoiiding'Siib- -m rubber p Oofthe series f rubberirads stanti'ally tothe'line Z 2 of'Figure lf Figure 3 rdisposedwwitniii casing Aic-i'I'hesupperisideiaof is a horizontal sectional view, correspondingisub thewwall i1 is recessed; to rprovide an upwardly Stantiany 1-, the 11 g 33-3 ,2 ""'Fig 4 :,openi.ngl-=seat' 12E adapted to; receivez'thevusual is an enlarged," vertical sectional view, partly Y p -fine centering p oiectionxofthe top follower broken away,'ofthe casingof myimprovfed shock svplatehof a-vclusterrof truck; springs jof a railway absorber; illustrating the structure of r the interior, scar. I

' lug'of the follower sleeve. of myimproved'lshock mar arranged withinlv the acasingfiA, :the; pads absorber is engaged. Figure 5 is a,top p1an.view sCe Ceecr-cicbeing superimposed. upon the-pad of the top rubberelementrandassociatedifric- MD. 2Thespads'C+C-i-i-C+;C are a1lr'ofn imi1 y d l of 'therrubber'relementsishowmiii'Figure 9.

tion plates. of my improved .shock'absorber; "Fig- I 3H1-sign, .vexcept: lass hereinafter pointed: out. i 1 Each are 6 is a perspective View of one-0ithe vfrietion pad C is in the form of a heavy rubber disc of plates. Figure 7 is a broken bottomiview Ofrthe -rzxdish'ediformatiomcpresenting a-rdepressedeonical follower shown in Figure 2. Figure 8 is avertical s fa-ce' :2! ongits lipp r :side sand a pr l'd seotionalview of a series ofrubber elements and 1: conicalsurfaceizii orritsbottom side-complemenfriction platesofmodified form. *Figure 9-. is a1 15o tary:. toathe rlepressedeonical surface-2i of the vertical sectional View.ofzthe top elementsshown wpad Cwwhichlis beneath the same." I he riibber in Figure 8. Figurei'lf). is atltopiplanzv'iew' ofi'one .ygpads Cfofithe series. are'iof progressively increas- :ring thickness, A consideried from-top to-sbottom of thewseriesfr The pad Dii n; the -form of a-ey-lin- Referring. firststonthe emb'odimient 'o-intheiinven- .rtionfillustratedzin :Figures 'Leto 'lsinclusiveyrmyil t:dricalsblockrreces'sed:at itsibottoni end to prdv'ide a conical seat 23, interfitting with the conical projection I I on the bottom wall Ill of the casing A. At its upper side, the rubber block D is provided with a depressed conical surface 24 complementary to the protruding bottom conical surface 22 of the lowermost pad C of the series of pads C--CC-C. a

The friction plates E comprise top and bottom sets EE and EE associated with each pad C, and a top set associated with the pad D. Each set of plates preferably comprises six plates arranged in annular series, each plate having in- :wardly converging side edges, which are radial to the central vertical axis of. the mechanism, and curved inner and outer edges. The plates E of each annular series are spaced apart cirfcumferentially of the mechanism, as shown in Figure 5. The sets of top and bottom plates E-E and E-E, associated with the pads C, are vulcanized to said pads, and the set of plates E-E, associated with the pad D, is vulcanized to the latter. As shown most clearly in Figure 2, the top plates E of the topmost pad C are engaged by the conical wedge projecton I 9 of the follower B and the set of bottom plates E of each pad C directly engages the set of plates E of the pad C which is therebeneath, with the exception of the bottom plates E of the lowermost pad C, which plates directly engage the top plates of the pad D. As will be evident, the cooperating plates E and E of the bottom and top sets of adjacent pads are capable of relative sliding movement with respect to each other and are in frictional contact.

The follower B has its upward movement away from the casing A limited, and is held assembled with the casing by radially outwardly projecting retaining lugs 25 engaged in the bayonet slots I3 and shouldering against the stop shoulders 26 formed by the transverse outer end walls of these slots.

My improved shock absorber preferably replaces one or more of the spring units of a truck spring cluster of a railway car, being interposed between the top and bottom spring plates of said cluster.

The operation of my improved shock absorber, as shown in Figures 1 to '7 inclusive, is as follows: Upon the spring cluster of the truck of a railway car being compressed between the spring follower plates of the cluster, the follower B is forced downwardly with respect to the casing A, thereby compressing the rubber pads CCC-C and D between the wedge projection I9 of the follower B and the conical projection I I on the bottom wall I of the casing A. During this compression of the rubber pads lengthwise of the mechanism, the pads are also placed under shear, due to the inclination of their cooperating surfaces and the ability of the metal plates associated with the pads to slide on each other. In addition to the resistance offered by the compression and shearing action of the rubber pads, frictional resistance is provided by relative sliding movement of the plates E-E on each other.

Referring next to the embodiment of the invention illustrated in Figures 8, 9, and 10, the structure shown in these figures comprises a series of rubber pads F-FF-F and G, and plates H, similar to the rubber pads CC-CC and D and plates E hereinbefore described, with the exception that the pads FF-F-F are in the form of rings, instead of discs, thus providing a central opening in each pad to permit freer 4 flow of the rubber of the pad and provide for greater shearing action, as well as greater relative movement, of the cooperating friction plates I-I--I-I with respect to each other.

As will be understood, the series of pads FFF--F and G, together with the plates H,

which are vulcanized to these pads, are employed with a casing and follower similar to the casing A and follower B hereinbefore described, being arranged within the casing in the same manner as the pads CC-C-C and D and the plates E.

Iclaim:

1. In a friction shock absorbing mechanism, the combination with a pair of members relatively movable toward and away from each other lengthwise of the mechanism; of yielding means interposed between and bearing on said members, respectively, said yielding means comprising a plurality of rubber pads arranged in series lengthwise of the mechanism, adjacent pads having respectively opposed, complementary surfaces diverging outwardly away from the longitudinal central axis of the mechanism, and two sets of friction plates with the plates of said sets in sliding contact with each other interposed between adjacent pads, said sets of plates being secured to said pads, respectively, certain plates of each set being at opposite sides of the longitudinal center line of the mechanism.

2. In a friction shock absorbing mechanism, the combination with a pair of members relatively movable toward and away from each other lengthwise of the mechanism; of yielding means interposed between and bearing on said members, said yielding means comprising a plurality of rubber pads arranged in series lengthwise of the mechanism, adjacent pads presenting opposed, complementary surfaces, said surface of each pad presenting portions diverging from the central longitudinal axis of the mechanism, and friction plates at opposite sides of the central longitudinal axis of the mechanism fixed respectively to said diverging surface portions of each pad, said plates of each pad being slidingly engaged with the friction plates of the adjacent pad.

3. In a friction shock absorbing mechanism, the combination with a pair of members relatively movable lengthwise of the mechanism toward and away from each other; of yielding means interposed between and bearing on said members, respectively, said yielding means comprising a plurality of adjacent rubber pads having opposed, complementary, conical surface portions, an annular series of friction plates fixed to said conical surface portions of each of said pads and slidingly engaged with the friction plates of the series fixed to the adjacent pad.

4. In a friction shock absorbing mechanism, the combination with a top member; of a bottom member, said top member being movable downwardly toward said bottom member; yielding means interposed between said members, said yielding means including a, plurality of rubber pads arranged in series vertically of the mechanism, adjacent of said pads having complementary, projecting and depressed surfaces, a set of annularly arranged friction plates secured to one of said complementary surfaces, and a second set of annularly arranged friction plates in sliding frictional contact with said first named set, said second named set being secured to the other of said complementary surfaces.

5. 'In a friction shock absorbing mechanism, the combination with a casing; of a top follower slidingly telescoped within the casing; a depending conical projection on said follower; a plurality of superimposed rubber pads arranged in series within said casing, the topmost pad having a depressed conical seat complementary to said conical projection of the follower; an annularly arranged series of friction plates interposed between said conical projection and said topmost pad, said plates being fixed to the la ter and having sliding contact with said conical projection, the opposed faces of adjacent pads of said series having complementary conical projections and conical depressions, and two sets of annularly arranged friction plates interposed between adjacent of said pads, the plates of one set being in frictional engagement, respectively, with the plates of the other set, and the plates of each of said respective sets being fixed to said adjacent pads, respectively.

6. In a friction shock absorbing mechanism, the combination with a pair of members relatively movable toward and away from each other lengthwise of the mechanism; of yielding means interposed between and bearing on said members, respectively, said yielding means compris ing a plurality of rubber discs arranged in series lengthwise of the mechanism, adjacent discs having respectively opposed, complementary surfaces diverging outwardly away from the longitudinal central axis of the mechanism, and two sets of contacting friction plates interposed between adjacent discs, the plates of one set being in sliding engagement with the plates of the other set, said sets of plates being secured to said discs, respectively.

7. In a friction shock absorbing mechanism, the combination with a pair of members relatively movable toward and away from each other lengthwise of the mechanism; of yielding means interposed between and bearing on said members, respectively, said yielding means comprising a plurality of rubber discs arranged in series lengthwise of the mechanism, each disc having a central opening therethrough, adjacent discs having respectively opposed, complementary surfaces diverging outwardly away from the central openings of said discs, and contacting sets of friction plates in sliding engagement with each other interposed between adjacent discs, and surrounding said openings of the discs, said respective sets of plates being secured to said discs, respectively.

8. A shock absorbing mechanism, adapted to be compressed between two members relatively movable toward each other, said mechanism comprising at least two rubber pads, and two sets of friction plates interposed between said pads, said pads being in longitudinal alignment lengthwise of the mechanism, the friction plates of each of said sets including a pair of plates at opposite sides of the longitudinal central axis of the mechanism, inclined toward each other, said pair of plates of said respective sets being secured to said pads respectively, said pair of plates of one of said sets being in sliding frictional engagement with said pair of plates of the other set.

9. In a friction shock absorbing mechanism, the combination with a pair of members relatively movable toward and away from each other lengthwise of the mechanism; of yielding means interposed between said members and compressible thereby upon relative approach of the same, said yielding means comprising a plurality of rubber pads arranged in series lengthwise of the mechanism, adjacent pads of said series having opposed complementary surface portions, each of said opposed surface portions including sections located at opposite sides of the longitudinal central axis of the mechanism, oppositely inclined with respect to each other, and oppositely inclined friction plates, respectively, at opposite sides of the central longitudinal axis of the mechanism secured to each of said opposed complementary surface portions of said pads, the plates which are secured to each of said 7 pads being in sliding frictional engagement with the plates of the adjacent pad.

HARRY W. MULCAHY.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 7,700 Ray Oct. 8, 1850 2,260,532 Lindeman Oct. 28, 1941 FOREIGN PATENTS Number Country Date 259,848 Great Britain Oct. 21, 1926 549,020 Great Britain Nov. 3, 1942 884,677 France May 3, 1943 

